The invention relates to a new and improved method for moving icebergs from one location to another in a body of water.
Icebergs constitute large masses of floating ice found in both the Northern and Southern Hemispheres. North Atlantic icebergs are formed from glaciers in the Artic Circle, i.e., the ice cap of Greenland, while South Alantic icebergs originate from the Antarctic ice shelf.
Icebergs are found in various shapes, sizes, and weights, and may continue growing in size in cold polar waters for indefinite periods, They may also drift under the influence of ocean currents to warm waters, whereby they melt and disintegrate by wave erosion and warmer temperatures.
Throughout the ages, icebergs have been known as a source of fresh water (as distinguished from frozen sea water) for sailors and sailing ships in distress. In modern times, there is an ever increasing interest in icebergs as a source of fresh water and cooling media, especially for arid or desert countries. However, there has been always the problem of moving or transporting the icebergs at low cost from the polar regions where they originate, to some other desirable destination. The tremendous mass, shape, and nature of icebergs make their transportation a complicated and formidable problem. Normally, ocean winds and ocean currents and temperatures determine the drift life and destination of icebergs.
There is therefore, a growing need for devising methods for safe and low cost transportation of icebergs from their natural drifting lanes to other more useful destinations.
Another factor stressing the need for developing such methods surfaces when icebergs drift into North and South Atlantic shipping lanes and fishing grounds, endangering the same for indefinite periods of time and becoming hazards to navigation.
Since usually only about one-seventh to one-tenth of the mass of an iceberg projects above the water, it is quite difficult for navigators approaching it to determine with any degree of accuracy the shape and dimensions of its submerged portion. During hours of darkness or during springtime, icebergs may be accompanied by a blanket of fog, which increases the danger to ships, passengers, and cargo at sea.
Many attempts were made in the past to reduce or eliminate the hazards introduced by drifting icebergs, through the use of tracking surveillance and detection methods. The known methods provide for the reduction of the hazard by disintegrating drifting icebergs by means of explosives and incendiary materials, or by covering the icebergs with lampblack to increase the rate of heat absorption and make them melt faster.
However, all these methods are costly and have serious drawbacks because they fail to dispose of all of the ice and thus are only partly successful in eliminating the hazards.
Current methods under development may be used for both the elimination of the aforesaid hazards to navigation, and for transporting icebergs to particular destinations, where the ice has a commercial valve, and according to these methods, the icebergs are physically moved by towing via lines attached to ships or boats. But these involve great expenditure of energy equipment and manpower.
These methods are highly inefficient and costly. Several large ships or tow boats moving at inefficient low speeds expend large amounts of energy for the movement of even a relatively small iceberg.
The overall efficiency from the standpoint of energy consumption of towing an iceberg by using tow ships or tow boats is in the area of 21/2 due to the low velocity involved, adverse effect of wake caused by towing vessels, and the non-parallelism of tow lines. The proposed system has an efficiency that is several times greater. This is due to the fact that the present invention eliminates the need for use of numerous towing ships, and reduces the parasitic weight of the towing medium by factors of 3 to 6. It also reduces, approximately 98% of the adverse reverse wake effect caused by the towing ship or ships. It also eliminates the losses due to the lack of combined parallelism of multiple towing ships.
With the proposed system, the problems described above are eliminated or reduced by approximately 100,000 to 1.
Another advantage of the present invention is that it eliminates calving or breaking up of the iceberg mass due to stress concentrations caused by driving and anchor forces of multiple tow lines attached to the iceberg. The preferred embodiment of the present invention contemplates feather-soft, uniform driving forces to move the iceberg without the need for boarding.
Also, when moving or transporting an iceberg, there is the problem of iceberg stability. During the voyage, under the conventional system, all tow lines must pull through the center of gravity to minimize tipping. Since an iceberg may melt unevenly, and as a result, shift in position and tumble in the water, severe hazards are involved in conventional towing methods which require attachment of tow lines, and the possibility of capsizing of towing boats is great. Also, melting causes a change in the center of gravity and relocation of attachment points of tow lines. The center of gravity, of course, is nearly impossible to locate, with any degree of accuracy.
The present invention goes a long way toward resolving all of these problems confronted in the prior art by providing for a low cost efficient and safe method for moving icebergs from one location to another, at a reduced melt rate.